Allergic and irritant reactions to plants and insects
Michael Gochfeld
gochfeld at eohsi.rutgers.edu
Tue Jul 31 05:40:07 EDT 2001
The mention of skin rashes and eye irritation from plants and insects is
not new, but it is obvious that under certain cases these reactions can
be severe and debilitating.
Irritant materials are generally "irritating" to a most people with some
variability in how individuals respond. And these reactions generally
involve a direct toxic effect on tissues or cells. Thus fiber glass and
sandpaper are irritating and there are many plant chemicals that are
irritants as well.
Allergic responses tend to be more idiosyncratic. Some are common (for
example 5-20% of a population might become sensitized to nickel or
mango) while others are rare (less than 1% of exposed people become
sensitized). And the reaction involves the immune system.
But, there may be source variability as well as receptor variability.
Milkweeds differ in their alkaloid composition, accounting for the
different palatability of the Monarch's that grow on them. Perhaps they
vary as well in their ability to inflict painful responses.
I regularly pull up Common Milkweed by hand and am exposed to the milky
"sap", but I certainly anticipate that if it ever got in my eye it would
be irritating.
Another difference is that irritant reactions may occur immediately
(within seconds or minutes). Allergic reactions may occur within
minutes (immediate hypersensitivity) or may take 24-48 hours to develop
(delayed hypersensitivity). These represent different immune
mechanisms.
It would be interesting to know how many people response adversely and
details about the nature of the response (localized at the point of
contact or general; symmetrical or asymmetrical).
Michael Gochfeld
------------------------------------------------------------
For subscription and related information about LEPS-L visit:
http://www.peabody.yale.edu/other/lepsl
More information about the Leps-l
mailing list